Sounds like you have a missfire on one or more cylinders. It happens, sometimes after throttle cleaning, where a piece of carbon is dislodged and bridges the spark gap on the plug. You can find the missfiring cylinder and curl your hair at the same time (ha ha!). Start the engine and let idle, if it will. With care and well insulated pliers, you can pull plug wires off one at a time. Pulling the "good" cylinders will cause the engine to stumble and possibly die. Pulling the missfiring cylinder will cause no change in the running. To make it easier to pull the wires off, you should remove the wire ends berore starting and loosly re-attatch them. Once you find the offending cylinder, you can remove the spark plug and clean it with a wire brush, spray it with carburetor cleaner and reinstall. See how it runs. If this doesn't fix it, or you can't determine the "missing" cylinder, take it back to the dealer who did the cleaning and see if they will diagnose and fix the problem Free Of Charge since the problem occured after they worked on it. If they are reputable, they should take care of it.
LOL.
Rick.